The setColumnVisible(key,visible) does not work anymore.

AG Grid: Since v31.1 api.setColumnVisible(key,visible) is deprecated. Please use setColumnsVisible([key],visible) instead.

The column methods have been migrated to the Grid API.

Read more:

• The Column API was deprecated in v31 and all methods were migrated to the Grid API.
• https://www.ag-grid.com/javascript-data-grid/column-api/

let isVisible = true; // or false
let columns = ['columnFieldKey1', 'columnFieldKey2'];    
let gridApi = agGrid.createGrid(gridDiv, gridOptions);
gridApi.setColumnsVisible(columns, isVisible);